Electroplating



UNITED STATES PATENT .oFFl'cE.l

THOMAS, A. EDISON, or LLEWELLYN PARK, WEST ORANGE, NEW JERSEY.

ELECTROPLATING.

Specification of Letters Patent.

Patented Nov. 23, 1920.

Application filed June 21, 1919. Serial No. 305,821.

l a citizen of the United States, and a resident of Llewellyn Park, West Orange, Essex county, New Jersey, have invented certain new and useful Improvements in Electroplating, of which the following is a description.

My invention relates to electro-plating, and more especially to the electro-plating of metals on metals.

When a metal is plated electrolytically directly upon another or the same metal, it is usually very difficult to separate, remove or strip the metal which is plated from the metal plated upon. This is especially truein the case of either nickel, copper or iron plated electrolytically on any of a'number of metals, including copper, nickel, and iron. As a matter of fact, generally in electroplating one of the main objects to be attained is to cause'the metal which is plated to firmly adhere to the member plated upon. The principal object of my invention, however, is to enable a metal electro-plated on4 a metal to be readily stripped or re- -moved therefrom, or in other words, to l prevent the metal plated from strongly adhering to the metal platedupon.-

I have discovered that when a metallic member is p-roperly treated so as to provide the same with a thin surface layer or film of a substance containing selenium or comprising a4 compound of selenium, such as ay selenid, a metal-electrolytically plated on the member so treated may be easily stripped therefrom without danger of injuring or defacing theopposed surfaces of said member and, metal, no matter how ldelicately they may be figured or designed; and in general, my invention. resides in a metallic member adapted to be electro-plated with metal and having a surface4 layer or film of this'- character, and also inthe process of providing the metallic member to be plated with such a layer or film.

While I shall specifically describe the application Iof my invention to the electroplating of nickel, copper and iron on a metallic member formed either of copper, nickel or iron, it is to be. distinctly under- 'stood that this is merely for the purposes of illustration, and that my invention is may equally applicable to the plating of any of the metals mentioned on members formed of metals other than copper, nickel, and 1ron,as well as to the plating of metals other than those `mentioned ony members- `formed of either copper, nickel or iron, or

any other suitable metal.

In carrying out my invention in the electro-plating of a member formed of either copper, nickel or iron with nickel, copper -or iron, I first preferably clean such member in a suitable manner so as to remove dirt and grease therefrom. The cleaned is formed will reduce the selenium from the selenious 4acid land combine therewith to produce on the surface of the member a thin integral surface layer or film of selenid of the metal. In case the member is formed of copper, it is subjected tothe action of the solution of selenious acid until the layer or film of selenid of copper formed thereon has a reddish tint and preferablyuntil such layer has a'dark red tint.

Nickel, copper or iron or any one of a number of othei1v metals, including silver, now be electro-plated on the member provided with the thin integral surface layer or film ofselenid in the usual manner and then stripped or removed therefrom.v The presence of the thin surf-ace layer or film of selenid enables any of these metals electroly-tically plated on this member to be'very readily removed or stripped .therefrom without danger of defacing the opposed surfaces of such metal and member. Incase the member plated is formed of copper, I .find

that best results are obtained when the film or layer of selenidof copper produced on such member has a dark red tint.-

Metals may be very economically provided with a surfacel layeror film such as described herein. For example, in the case of copper, three cubic centimeters of a solution of selenious acid containing five per cent. of selenium, when mixed with two hundred cubic centimeters of water, will suflice to cover a surface'having anarea of one and a one-half square feet with a film ofiselenid of copper having a dark red tint.

In the drawing accompanyingv and forni ing a part ofthis specication, the -single figure is a view in perspective, partly broken away, showing a metallic member provided with a surface layer or film in accordance with my invention.

Referring to the drawing, reference character l represents a metallic member such v as a member of copper, on which it is desired to electro-plate another metal. The member l is provided with a thin surface layer or film 2 consisting of a material containing selenium such as selenid of copper, in the manner above described, so as to enable the metal which may be electro-plated on member l, to be readily stripped therefrom. The thickness of the layer or film 2 is shown greatly exaggerated.

It is to be understood that my invention' is not to be limited tothe platino' of metals on nickel, iron and copper only, ora member formed of any metal which will reduce selenium from selenious acid will, when im- Inersed in a solution of selenious acid, automatically' receive or be, provided with a thin surface layer or film of the selenid of the metal, which film will, as mentioned above,

'facilitate the stripping from such member ofa metal electro-plated thereon.

Having now described my invention, what I claim as new and desire to protect by Letters Patent isas follows v l. A metallic member upon which a metal is adapted to be plated electrolytically, having a thin surface layer or film consisting of a material containing selenium, substantially as described. f

2. is adapted to be plated electrolytically, having chemically formed `thereon a surface layer consisting of a compound of the metal of which said member is formed and selenium, substantially as described.

3. A metallic member upon which a metal is adapted to be plated electrolytically, having a surface layer formed integrally With such member and consisting" of a material containing selenium, substantially as described.

4. A metallic member upon which a metal is adapted to be plated electrolytically, having a surface layer chemically formed integrally with such member and consisting of a compound of the metal of which said member is formed and selenium, substantially as described.

5. A member formed of copper and provided with a surface layer of selenid of pepper, substantially vas described.

6. A`member formed of copperand Cpro- 1 A metallic member upon which a metal vided with av surface layer consisting of a compound of selenium and copper, substantially as described.

7. A member formed of copper and provided with a surface layer of selenid of copper chemically formed integrally With such member, substantially as described.

l0. The process of treating a metallic v member upon which a metal is to be plated electrolytically, which consists in chemically forming thereon a surface layer of a substance containing selenium, substantially as described. ,i

11. The process ofv treating va metallic member which consists in cleaning said member and then forming thereon a surface layer of a compound of selenium, substantially as described.

12. The process of treating a member consisting of a metal capable of reducing Sele-- nium from selenious acid, which consists in chemically forming on such member a surface layer consisting of a compound of such y metal and seleniumy by subjecting themember to the action of selenious acid, substantially as described.

13. The process of treating a member having a surface portion formed of metal capable of reducing selenium from selenious acid, which consists in chemically forming on said surface portion a thin layer or film consisting of a compound containing selenium by subjecting such surface portion to the action of selenious acid, substantially as described. v

14. The process of treating a. member formed of copper, which consists in subjecting the member to the action of selenious acid, substantially as described. v

15. The process Iof treating a member formed of copper, which consists in subjecting suchmember to the action of selenious acid until the surface of. such member becomes covered with a thin layeror yhlm of selenid of copper having a reddish tint, substantially'as described. p I Y This specification signed this 18th day of June 1919.

THOS. A. EDSON.` 

